U.S. patent application number 16/711478 was filed with the patent office on 2020-04-16 for fastening systems comprising nonwoven substrates with hooks formed integrally thereon.
The applicant listed for this patent is The Procter & Gamble Company. Invention is credited to Russell Andrew HAYDEN, James David LANDGREBE, Nayda Liz RAMOS MEDINA, Jeromy Thomas RAYCHECK, Abhishek Prakash SURUSHE.
Application Number | 20200113749 16/711478 |
Document ID | / |
Family ID | 67841203 |
Filed Date | 2020-04-16 |
View All Diagrams
United States Patent
Application |
20200113749 |
Kind Code |
A1 |
SURUSHE; Abhishek Prakash ;
et al. |
April 16, 2020 |
FASTENING SYSTEMS COMPRISING NONWOVEN SUBSTRATES WITH HOOKS FORMED
INTEGRALLY THEREON
Abstract
A wearable article includes hook-and-loop fastening components.
The hook-and-loop fastening components have a section of nonwoven
web material on which an array of hooks is formed. At least some of
the hooks may be integrally formed from the nonwoven material. The
section of nonwoven web material may also include a section of
loops material, wherein at least some of the loops may be
integrally formed from the web material. The section of loops
material may have a machine direction dimension of at least 20 mm
and a cross direction dimension of at least 20 mm, and a surface
area of at least 314 mm.sup.2. The article may further include an
identifiable linear path, the identifiable linear path having a
width greater than 2 mm and forming an angle with the machine
direction of 45 degrees or less. Any such identifiable path at
least partially overlies the loops-forming bond(s), at a plurality
of locations along the identifiable linear path.
Inventors: |
SURUSHE; Abhishek Prakash;
(Schwalbach am Taunus, DE) ; HAYDEN; Russell Andrew;
(New Richmond, OH) ; LANDGREBE; James David;
(Madeira, OH) ; RAYCHECK; Jeromy Thomas; (South
Lebanon, OH) ; RAMOS MEDINA; Nayda Liz; (Cincinnati,
OH) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
The Procter & Gamble Company |
Cincinnati |
OH |
US |
|
|
Family ID: |
67841203 |
Appl. No.: |
16/711478 |
Filed: |
December 12, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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16545425 |
Aug 20, 2019 |
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16711478 |
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62720554 |
Aug 21, 2018 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A44B 18/0011 20130101;
A61F 13/627 20130101; A61F 13/625 20130101; A44B 18/0049 20130101;
A61F 13/5633 20130101; A44B 18/0015 20130101 |
International
Class: |
A61F 13/56 20060101
A61F013/56; A44B 18/00 20060101 A44B018/00; A61F 13/62 20060101
A61F013/62 |
Claims
1. A disposable open-form diaper, comprising: a chassis comprising
a liquid permeable topsheet, a liquid impermeable backsheet and an
absorbent core structure disposed between the topsheet and the
backsheet; a front waist region; a rear waist region; and a crotch
region disposed between the front waist region and the rear waist
region; a longitudinal axis and a lateral axis; a fastening member
joined to the chassis in the rear waist region and extending
laterally away from the longitudinal axis, including a first
fastening component disposed thereon; and a second fastening
component disposed on the front waist region; wherein one or both
of the first and second fastening components comprises a section of
nonwoven web material on which an array of hooks is formed, wherein
the section of web material comprises filaments of polymeric
material; and wherein at least a portion of the array comprises
integral hooks, wherein said integral hooks are thermally formed at
least in part of the polymeric material of the filaments such that
said integral hooks are integral with the nonwoven web
material.
2. The diaper of claim 1, wherein the integral hooks is formed on a
wearer-facing surface of the fastening member.
3. The diaper of claim 1, wherein the integral hooks is formed on
an outward-facing surface of the front waist region.
4. The diaper of claim 1, wherein one or more hooks are imparted
with unidirectionality along a direction that is 45 degrees or less
with respect to the lateral axis.
5. The diaper of claim 1, wherein one or more hooks are imparted
with bidirectionality along a direction that is 45 degrees or less
with respect to the lateral axis.
6. The diaper of claim 1, wherein one or more hooks are imparted
with directionality toward the longitudinal axis.
7. The diaper of claim 1, wherein the array of hooks has a machine
direction dimension of at least about 20 mm.
8. The diaper of claim 1, wherein the array of hooks comprises a
curvilinear shape.
9. The diaper of claim 1, wherein the array of hooks comprises a
plurality of discrete, discontinuous areas of hooks formation
interspersed in and within a second continuous area of the nonwoven
web material where no hooks are formed.
10. The diaper of claim 1, wherein the array of hooks comprises at
least one continuous area of hooks formation, surrounding at least
one discontinuous area of the nonwoven web material in which no
hooks are formed.
11. The diaper of claim 1, wherein at least some of the hooks are
integrally formed at least in part of a second polymeric material
supplementing the polymeric material of the filaments.
12. The diaper of claim 1, wherein the section of nonwoven material
is discrete from and attached to the backsheet.
13. The diaper of claim 1, wherein when the section of nonwoven web
material is deemed to lie along an x-y plane, the hooks are formed
to extend in a z-direction with respect to the x-y plane, and the
hooks comprise a first plurality of hooks that hook over in a first
direction and a second plurality of hooks that hook over in a
direction differing from the first direction.
14. The diaper of claim 13 wherein the section of nonwoven web
material is disposed on the front waist region, the first plurality
of hooks is disposed on the web material proximate a left side of
the front waist region, and the second plurality of hooks is
disposed on the web material proximate a right side of the front
waist region.
15. The diaper of claim 1 wherein the array of hooks is set back
from one or more edges of the section of nonwoven web material.
16. A disposable open-form diaper, comprising: a chassis comprising
a liquid permeable topsheet, a liquid impermeable backsheet and an
absorbent core structure disposed between the topsheet and the
backsheet; a front waist region; a rear waist region; and a crotch
region disposed between the front waist region and the rear waist
region; a longitudinal axis and a lateral axis; a first fastening
component disposed in one of the front or rear waist regions; a
second fastening component disposed in another of the front or rear
waist regions; wherein the first fastening component comprises a
discrete patch of hooks; and wherein the second fastening component
comprises a plurality of integral hooks, the integral hooks being
formed at least in part of a section of material on which an array
of hooks is formed.
17. The diaper of claim 16 wherein the second fastening component
is disposed in the first waist region.
18. The diaper of claim 16 wherein the plurality of integral hooks
is imparted with multidirectional directionality.
19. The diaper of claim 16 wherein the section of material on which
the array of hooks is formed further comprises a section of loops
material adapted to cooperate with the first fastening
component.
20. The diaper of claim 16, wherein when the section of material on
which the array of hooks is formed is deemed to lie along an x-y
plane, the hooks are formed to extend in a z-direction with respect
to the x-y plane, and the hooks comprise a first plurality of hooks
that hook over in a first direction and a second plurality of hooks
that hook over in a direction differing from the first direction.
Description
BACKGROUND
[0001] Hook-and-loop fastening systems have been used in a variety
of applications for a number of years. Such applications have
included fastening systems for wearable garments and articles,
including but not limited to disposable diapers. One currently
popular configuration of disposable diaper/fastening system
includes an absorbent chassis having a front waist region, crotch
region and rear waist region, with a pair of fastening members each
extending respectively laterally from left and right longitudinal
edges of the chassis in the rear waist region. In a typical
configuration, each fastening member includes a patch of material
bearing hooks, affixed to the wearer-facing side of the fastening
member. A patch or section of cooperating loops material is
typically disposed on the outward-facing side of the front waist
region. In this configuration, the chassis may be wrapped through
the wearer's crotch area with the back waist region placed across
the wearer's lower back and buttocks and the front waist region
placed across the wearer's lower belly area. The left and right
fastening members may then be wrapped about the wearer's left and
right hips, respectively, and fastened to the front waist region
via engagement of the hooks patches with the loops material on the
front waist region, thereby securing the diaper on the wearer.
[0002] Hooks of various designs for use with various types of loops
material have been developed over the years, as have techniques for
efficiently manufacturing hooks. Manufacturers of hooks have
included the Velcro Companies (United Kingdom), 3M Company
(Minnesota, USA) and Aplix (France). One technique has included
heating thermoplastic resin in an extruder, extruding a base sheet
and then molding and/or otherwise forming hooks into one face of
the base sheet from the material thereof, while it is still soft or
partially molten. Another technique has included extruding a
continuous structure having a base sheet portion and a series of
extruded formations extending from the base sheet portion having
desired hook profiles. Following extrusion, a series of cuts
through the formations are made along a direction transverse to the
extrusion direction to create rows of hooks structures, without
cutting through the base portion. The base sheet with rows of hooks
structures is then plastically stretched along the extrusion
direction, to create or enlarge separation between the rows of
hooks structures. In many applications, a layer of suitable
adhesive may be applied to the underside of the base material. The
combination of hooks/base sheet material and adhesive may then be
cut to any commercially desired size or shape, such as strips, and
may be gathered, e.g., on a roll, for delivery to the
purchaser/user. The purchaser/user may further cut the product to a
desired size (e.g. a hooks patch) to be affixed to an article and
thereby provide the hooks component of a hook-and-loop fastening
system for the article.
[0003] More recently, techniques have been developed that enable
formation of patterns of hooks directly on a preexisting substrate,
such as a film or nonwoven. Such techniques may provide a benefit
in elimination of processing and handling steps involving hooks
materials and manufacture of articles with hook-and-loop fastening
systems, including disposable diapers. However, it is believed that
these techniques and the benefits they may provide in a variety of
particular applications have not been fully developed or
appreciated.
SUMMARY OF INVENTION
[0004] A wearable article may include a section of nonwoven web
material having a machine direction of formation (MD). The section
of nonwoven material comprises filaments of polymeric material and
an array of hooks. At least some of the hooks may be integrally
molded in part of the polymeric material of the filaments. The
section of nonwoven material may also comprise a loops material
having a plurality of loops, and at least some are integrally
formed from the nonwoven material.
[0005] In some embodiments, the wearable article may be in the form
of a diaper, having a chassis comprising a liquid permeable
topsheet, a liquid impermeable backsheet and an absorbent core
structure disposed between the topsheet and the backsheet. The
diaper may include a fastening member joined to the chassis in the
rear waist region and extending laterally away from the
longitudinal axis, including a first fastening component disposed
thereon; and a second fastening component located on the front
waist region. One of both of the first and second fastening
components comprises a section of nonwoven web material on which an
array of hooks is formed, wherein the section of web material
comprises filaments of polymeric material. The section of nonwoven
web material has a machine direction of formation, and the
filaments of polymeric material having a machine direction bias and
are consolidated and bonded in a pattern of thermal bonds. The
section of nonwoven web material may also comprise a section of
loops material having a machine direction dimension of at least 20
mm, a cross direction dimension of at least 20 mm, and a surface
area of at least 314 mm.sup.2, and being bonded in a continuous
loops-forming bond, or pattern of discrete loops-forming bonds. Any
identifiable linear path along the section of loops material that
has a width greater than 2 mm and forms an angle of 45 degrees or
less with the machine direction (MD) at least partially overlies
the loops-forming bond or bonds in the pattern, at a plurality of
locations along the identifiable path. At least some of the hooks
may be thermally formed at least in part of the polymeric material
of the filaments such that at least part of the array is integral
with the nonwoven web material.
[0006] The disclosure further includes a method for producing a
fastening component material having both hook elements and loop
elements, comprising the steps of:
[0007] spinning a plurality of filaments from one or more polymeric
resins, and depositing the spun filaments onto a belt moving along
a machine direction to form a batt of the filaments;
[0008] conveying the batt via the moving belt to a nip between one
or more pairs of rollers and/or a nip between a roller and an
ultrasonically vibrating surface,
[0009] wherein at least one roller among one or more pairs of
rollers and/or roller and ultrasonically vibrating surface
comprises bonding protrusions arranged in a pattern along a surface
thereof;
[0010] wherein at least one roller among one or more pairs of
rollers and/or roller and ultrasonically vibrating surface
comprises hooks-forming cavities arranged along a surface
thereof;
[0011] consolidating the batt and bonding the filaments together in
a pattern of thermal bonds via the bonding protrusions, forming a
bonded nonwoven web; and
[0012] forming an arrangement of hooks from polymeric material of
the filaments via the hooks-forming cavities, wherein the
arrangement of hooks are integral with the bonded nonwoven web.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a perspective view of an example of a disposable
diaper as it might appear in a relaxed condition prior to
application to an infant-wearer.
[0014] FIG. 2 is a plan view of the diaper of FIG. 1, shown
extended against contraction induced by elastomeric components, to
substantially the full dimensions of its non-elastic components,
shown with wearer-facing surfaces facing the viewer.
[0015] FIG. 3 is a plan view of the diaper of FIG. 1, shown
extended against contraction induced by elastomeric components, to
substantially the full dimensions of its non-elastic components,
shown with outward-facing surfaces facing the viewer.
[0016] FIG. 4 is a plan view of a section of web material to which
a strip of hooks material has been applied.
[0017] FIG. 5 is a plan view of an example of a fastening member
cut from the web material shown in FIG. 4.
[0018] FIGS. 6A-6C are schematic side-view depictions of
configurations of equipment and a schematic representation of
examples of processes for manufacturing a bonded nonwoven web
material with integrally molded arrays of hooks.
[0019] FIGS. 7A-7E are schematic cross-section views taken along a
cross direction through exemplary web materials on which areas of
hooks have been integrally molded.
[0020] FIG. 8A is a plan view of a section of web material upon
which a strip of hooks has been integrally molded.
[0021] FIG. 8B is a plan view of an example of a fastening member
cut from the web material shown in FIG. 8A.
[0022] FIG. 8C is a plan view of another example of a section of
web material upon which a strip of hooks has been integrally
molded, having areas that have been subsequently deactivated or
flattened.
[0023] FIG. 8D is a plan view of an example of a fastening member
cut from the web material shown in FIG. 8C.
[0024] FIG. 8E is a plan view of another example of a section of
web material upon which discrete areas of hooks have been
integrally molded.
[0025] FIG. 8F is a plan view of an example of a fastening member
cut from the web material shown in FIG. 8E.
[0026] FIG. 8G is a plan view of a section of web material upon
which discrete areas of hooks have been integrally molded, wherein
the web material includes an elasticized zone.
[0027] FIG. 8H is a schematic cross section of the section of web
material shown in FIG. 7G, taken through line 8H-8H in FIG. 8G, and
shown with layers separated.
[0028] FIGS. 9A-9E are depictions of various examples of
arrangements of areas of hooks.
[0029] FIGS. 10A-10I and 11A-11C are depictions of various examples
of bonding patterns on sections of nonwoven loops material.
[0030] FIGS. 12A-12E are depictions of various examples of sections
of web material upon which examples of hooks arrangements might be
formed for use on a diaper.
[0031] FIG. 12F is a plan view of a diaper, shown extended against
contraction induced by elastomeric components, to substantially the
full dimensions of its non-elastic components, shown with
outward-facing surfaces facing the viewer.
[0032] FIGS. 13A-13C are schematic views of combinations of
examples of front and rear waist regions of diapers with various
combinations of fastening component configurations.
[0033] FIGS. 14A-14C, 15A-15C, and 16A-16C depict front, side and
top views of examples of profiles of hooks protruding from a
substrate.
DETAILED DESCRIPTION
Definitions
[0034] "Elastic" or "elastomeric" refers to the property of a
material such as a stretch laminate material that elongates,
without substantial rupture or breakage, by at least 50% at a load
of between 0.1 and 10 N/cm in the Hysteresis Test. Rupture or
breakage having a dimension less than 5 mm in any direction is not
considered substantial rupture or breakage. However, ruptures
through the structure having a dimension greater than 5 mm in any
direction, breaks, ruptures or tears into two or more pieces, or
breaks, ruptures or tears resulting in significant structural
degradation which render the material unusable for its intended
purpose, are considered substantial ruptures or breakage. Further,
upon release of the load, the elastic material has a set less than
or equal to 20% as measured by the Hysteresis Test. For example, an
elastic material that has an initial length of 25 millimeters can
elongate to at least 37.5 millimeters (50% elongation) and, upon
removal of the force, retract to a length of 27.5 millimeters,
i.e., have a set of 2.5 millimeters (10% set), when subjected to
the Hysteresis Test.
[0035] With respect to hooks, as used herein, the term "integrally
molded" and variants thereof refers to hooks that are molded
directly onto a substrate, partially or entirely from thermoplastic
material of which the substrate is formed, via equipment having
mold cavities, and equipment providing heating energy. Accordingly,
integrally molded hooks and the substrate on which they are formed
will have one or more thermoplastic component materials in
common.
[0036] "Lateral," with respect to a diaper or components thereof,
refers to the direction that is parallel to the waist edges of the
diaper when it is open and laid out flat along a horizontal
plane.
[0037] "Like chemistry," with respect to two polymeric
compositions, means that the two compositions are capable of mixing
together at a temperature of 250 deg. C. or lower, to form a single
thermodynamic phase.
[0038] "Longitudinal," with respect to a diaper or components
thereof, refers to the direction that is perpendicular to the waist
edges of the diaper when it is open and laid out flat along a
horizontal plane.
[0039] "Machine direction," with respect to manufacture of nonwoven
web material, means the direction along which the web material is
formed and moves through a nip between calender/bonding rolls.
[0040] "Machine direction bias," with respect to filaments forming
a spunbond nonwoven web material, means that a majority of the
filaments, as situated in the web material and unstretched, have
lengths with machine direction vector components that are greater
than their cross direction vector components.
[0041] "Cross direction," with respect to manufacture of nonwoven
web material, means the direction perpendicular to the machine
direction, along an x-y plane occupied by the web material.
"Outward-facing," with respect to surfaces of components of a
diaper, means the surfaces that face away from the wearer's body
when the diaper is worn.
[0042] "Wearer-facing," with respect to surfaces of components of a
diaper, means the surfaces that face the wearer's body when the
diaper is worn.
[0043] "z-direction," with respect to a web material, is the
direction orthogonal to an x-y plane occupied by the web material
when laid out flat.
[0044] Wearable Articles
[0045] FIG. 1 depicts an example of a wearable article 10 in the
form of a disposable, open-form diaper 100, as it might appear in a
relaxed condition at rest on a table, prior to donning on an
infant. FIGS. 2 and 3 depict plan views of the wearer-facing
surfaces 11 and outward-facing surfaces 12, respectively, of the
diaper of FIG. 1, laid out flat and extended to the full dimensions
of its non-elastic components. A typical disposable diaper includes
a chassis 100a with a front waist region 101, rear waist region 102
and crotch region 103, longitudinal axis 104 equally dividing the
width of the chassis, and lateral axis 105 equally dividing the
length of the chassis, longitudinal edges 106, front waist edge 107
and rear waist edge 108. The front waist region lies entirely to
the front of the lateral axis 105; the rear waist region lies
entirely to the rear of the lateral axis 105, and the crotch region
longitudinally straddles the lateral axis 105.
[0046] Chassis 100a may be formed of a liquid-permeable topsheet
111 which forms a large portion of the wearer-facing surfaces; a
liquid-impermeable backsheet 112 which forms a large portion of the
outward-facing surfaces, and an absorbent core structure (not
shown) disposed between the topsheet and a backsheet, within an
enveloping structure formed by the assembly of topsheet and
backsheet. The article 10 may also include a pair of elasticized
outer leg cuffs 106, and a pair of elasticized inner barrier cuffs
115, which together serve dual purposes of providing for
containment of wearer exudates and providing a neat, fitted
appearance about the wearer's legs. These cuff structures may be
formed separately or as an integral structure and assembled to
overlay the wearer-facing side of the chassis 100a. The article may
also include an elasticized waistband in the front waist region
and/or an elasticized waistband in the rear waist region.
[0047] Diaper 100 also may include one or more fastening members
120, such as a pair of left and right fastening members 120 each
affixed to and respectively extending laterally away from the
longitudinal axis and the respective left and right longitudinal
edges 106 of the chassis. Diaper 100 also may include a landing
zone 130 on the front waist region. Fastening members 120 and
landing zone 130 may include respective cooperating fastening
components that enable fastening of fastening members 120 at
locations proximate their laterally distal ends, to the landing
zone 130. Thus, diaper 100 may be donned on an infant wearer with
the rear waist region 102 covering the wearer's buttocks, the
crotch region 103 wrapping under the wearer's lower torso between
the legs, and the front waist region covering the wearer's lower
front torso; and the fastening member 120 may be wrapped about a
hip and then fastened at the landing zone 130, thereby fastening
the diaper about and on the wearer. In some examples, fastening
members 120 may be formed of, or include sections of, a stretch
laminate material that imparts elastic stretchability and
contractibility to the fastening members 120 along the lateral
direction, enhancing the fit and comfort of the diaper for the
wearer.
[0048] Non-limiting examples of suitable diaper and fastening
member configurations are described and depicted in, for example,
US 2018/0200125, and references cited therein.
[0049] Hooks Configurations; Hooks Formation In many current
examples of disposable diapers, fastening members 120 include
patches of hooks adhered to wearer-facing surfaces of the fastening
members 120, proximate their laterally distal ends.
Correspondingly, in such examples the landing zone 130 will include
a material adapted to fastenably cooperate with the hooks, such as
section or patch of material adapted to serve as cooperative loops
material, to provide a hook-and-loop fastening system combination.
In some embodiments, the landing zone comprises a discrete material
(e.g., a discrete path of loops material) that may be attached to
the backsheet or other portion of the diaper. In some embodiments,
the landing zone 130 may be integral with one or more portions of
the diaper (e.g., loops material formed from or otherwise integral
with said portions), such as one or more portions of the backsheet
112.
[0050] Referring to FIGS. 4 and 5, frequently, fastening members
120 with hooks patches 121 have been manufactured by providing a
continuous web of fastening member substrate material 122,
conveying it along a machine direction MD, unrolling hooks material
strip from a rolled supply thereof and continuously adhering or
bonding the strip 123 to the substrate material 122, and then
cutting the substrate material with the adhered hooks strip along
fastening member cut paths 124 that trace the profile desired for
the fastening members 120, generally along directions transverse to
the direction the hooks strip 123 was unrolled. As suggested in
FIG. 4, for manufacturing efficiency and minimization of cut-off
waste, the fastening member profiles and associated cut paths 124
may be nested along the substrate material. In the resulting
cut-out fastening member 120 as reflected in FIG. 5, the hooks
patch 121 is coextensive with the fastening member along the
direction in which the hooks material strip was unrolled. It will
be appreciated that this process involves the necessity of
procuring a supply of hooks strip material 123, and providing
equipment and process steps to unroll and adhere or bond the hooks
material strip to the fastening member substrate 122. It will be
appreciated further that this process creates constraints with
respect to the size, shape and placement of the hooks patch
relative the fastening member, including, among other constraints,
that the resulting hooks patch 121 will be coextensive in machine
direction length and shape with the cut lines 124.
[0051] More recently, integrally molding hooks directly on a
substrate material has been proposed, wherein the substrate
material serves not only as a structural component material for
other purposes, but also as the source of polymer material for
formation of the hooks; see, e.g., U.S. Pat. Nos. 8,784,722;
6,478,784 and 6,746,434. Products of these processes or similar
processes are currently marketed by Soni-Form, LLC and/or Creative
Machine Designs, Inc., both of Derry, N.H. These methods involve
conveying a suitable substrate along a machine direction to a
molding roll having hook-forming cavities formed in and along a
circumferential molding surface thereof, combined with an opposing
roller or other body providing an opposing surface, and a source of
heating energy (for example, ultrasonic vibratory energy), to heat
and soften a portion of the polymeric material of the substrate and
press it into the hook-forming cavities. As the substrate leaves
the molding roll/opposing surface combination, it has an array of
hooks formed directly thereon, integral with the material of the
substrate. It may be appreciated that when used with a suitable
substrate, this process might be used to eliminate the need for
process steps and materials associated with obtaining and supplying
a strip of hooks material and applying and adhering or bonding it
to the substrate, in order to provide a substrate bearing
hooks.
[0052] In a further application, the processes of forming nonwoven
web material and forming hooks thereon might be combined in a
single continuous process. Referring to FIGS. 6A and 6B, a bonded
spunbond web may be formed by urging under pressure suitably
selected polymeric material or materials in heated (molten) state
through a beam of spinnerets 200 to spin filaments 201 and direct
them to a conveyor surface 202 moving along a machine direction MD.
As the spun filaments 201 strike the conveyor surface 202, they
accumulate to form a batt 203 or deposition of unconsolidated
filaments on the surface. Those of ordinary skill in the art of
nonwoven web manufacturing appreciate that the basis weight of the
batt 203 and of the finished web may be adjusted and controlled by
controlling process variables such as, but limited to, the size of
the beam of spinnerets 200 and numerical/spatial density of
individual spinnerets therein; the rate at which polymer material
is urged through the beam; and the speed at which the conveyor is
operated. The filaments generally strike and come to rest within
the batt on the conveyor surface in partially random but partially
machine-direction biased directional orientations, as a result of
machine direction movement of the conveyor surface as it receives
the spun filaments.
[0053] The batt 203 may then be conveyed into the nip between a
pair of calender/bonding rollers including a bonding roller 204
having bonding protrusions 205 arranged in a pattern and extending
radially outwardly from the circumferential surface of the bonding
roller, and an opposing anvil roller 206. A source of heating
energy may be supplied proximate the nip. In some examples, one or
both of the bonding roller 204 and anvil roller 206 may be heated.
As the batt 203 moves into the nip, it is compressed along a
z-direction and pressure on the batt is concentrated in the areas
where the bonding protrusions approach the opposing surface of the
anvil roller, resulting in at least partial melting and fusing of
filaments beneath the bonding protrusions, and then resulting in a
consolidated, bonded nonwoven web 207 with an impressed pattern of
bonds that approximately correspond in size, shape and arrangement
with the pattern of bonding protrusions on the bonding roller
204.
[0054] In some examples, the bonded nonwoven web 207 may be
laminated with another similarly-formed nonwoven web, or a
polymeric film, or both, to form a laminate web that includes two
or more layers including the bonded nonwoven web 207.
[0055] Directly or indirectly downstream of the calender/bonding
rollers, or laminating rollers, but disposed so as to perform steps
in a continuous part of the same web processing operation, a
hooks-forming roller 208 may be disposed. Hooks-forming roller 208
may have formed into its circumferential surface a pattern of
hooks-forming cavities 209, configured to mold one or more
continuous or discontinuous areas of hooks of desired shape, size,
directional orientation, pattern, density and area shape and size.
A source of heating energy such as, for example, ultrasonic
vibratory energy (provided via, e.g., an ultrasonic horn or
sonotrode 210a or a rotary ultrasonic horn 210b) may be disposed in
opposition to the hooks-forming roller 208 to form a second nip. As
the bonded nonwoven web 207 passes through the second nip, heating
of the polymeric material of the filaments, by application of the
heating energy, softens it so that it may be deformed and forced,
in the second nip, into the hooks-forming cavities 209 of the
hooks-forming roller. The hooks-forming roller 208 may be cooled or
otherwise temperature-controlled to help assure that the finished
web 211 will emerge from the second nip with formations of hooks
that are stably formed and solidified. The resulting hooks and
areas thereof on the emerged finished web 211 will be molded from
and thereby physically integral with material(s) of which the
nonwoven web material and/or laminate web is formed. Similar to the
manner in which the pattern of bonds in the material correspond
with the pattern of bonding protrusions on the bonding roller 204,
the pattern of and shape of hooks that result on the finished web
211 will approximately correspond with the arrangement and features
of the hooks-forming cavities 209 in the hooks-forming roller
208.
[0056] In another example, bonding protrusions and hooks-forming
cavities might both be formed on a single combination
bonding/hooks-forming roller. One or more of an anvil roller,
heated anvil roller and a rotary ultrasonic horn may be disposed in
opposition to the bonding/hooks-forming roller to form a nip
therewith. A bonded nonwoven web bearing one or more areas of
integrally molded hooks may be formed in single step by passing the
batt of spun filaments through this nip.
[0057] Referring to FIGS. 6C and 7B-7E, in some examples, it may be
desired to provide supplemental thermoplastic polymer material 113s
for molding hooks and forming a base structure therefor, over the
web material 211, as suggested in FIGS. 7B and 7C, beneath the web
material as suggested in FIG. 7D, or in some examples, by folding
the web material 211 over on itself, as suggested in FIG. 7E
(illustrating a non-limiting example of a Z-fold 113f of web
material 211 with fold lines along the machine direction). In some
examples, a supplemental thermoplastic polymeric material may be
introduced upstream of the nip between the hooks-forming roller to
provide the supplemental material 113s for forming integrally
molded hooks. Referring to the example of a processing system
illustrated in FIG. 6C, a selected quantity of supplemental
material may be introduced to the web by a supplemental material
delivery system 113, in a position along the web where it, in
combination with the polymeric material forming the filaments, will
be subject to the heating energy (e.g., ultrasonic vibratory
energy) and be in suitable position to be at least partially urged
into the hooks-forming cavities in hooks-forming roll 208. It may
be desired that the supplemental polymeric material have
substantially the same composition as the polymeric material from
which the filaments are spun, or is otherwise of like chemistry
therewith, to ensure that the polymeric material from which the
filaments are spun and the supplemental polymeric material become
suitably blended/merged and integral during and following formation
of hooks and cooling. The supplemental polymeric material may have
the form of a strip of film or nonwoven web material introduced
along the machine direction, in line with the hooks-forming
cavities, a deposition of molten polymeric material applied to the
web either continuously or intermittently, etc.
[0058] Now referring to FIGS. 8A and 8C, in some examples, using
suitably configured equipment, a continuous strip of hooks area
212, the strip being aligned with the machine direction, may be
integrally molded on the substrate web material 211, such that
integrally molded hooks extend to and through the upstream and
downstream cut paths 124 and resulting cut edges of fastening
members in the manner suggested in FIGS. 8B and 8D. In some more
particular examples, such integrally molded hooks proximate the cut
paths 124 or cut edges of the fastening members may be flattened in
areas 212d by subsequent rolling or other suitable technique, to
blunt or flatten the hooks and/or smooth the fastening members
along their cut edges. This may be desired for aesthetic purposes,
or to blunt/flatten hooks integrally molded on the fastening
members in positions along the cut edges, decrease risk of wearer
skin abrasion and/or irritation therefrom.
[0059] Using a process as described above, however, and referring
to FIGS. 8E and 8F, a finished web material 211 with integrally
molded, discrete and separate areas of hooks 212 may be formed.
Hooks-forming cavities may be formed and arranged on a
hooks-forming roller in any desired configuration of hook size,
shape, number, density, placement pattern, and arrangement of areas
of hooks.
[0060] Using the online hooks molding process described, the
practical constraints and/or costs presented by supply and
application of a continuous strip of pre-manufactured hooks
material are eliminated, and the areas of hooks may be provided on
the nonwoven material in any desired configuration, such as the
configurations reflected in FIGS. 8A-8G. Additional illustrative
but non-limiting examples of hooks area configurations are depicted
in FIGS. 9A-9E. It can be appreciated that areas of hooks may be
configured in any desired size, shape, pattern, directionality of
hooks orientation, number of hooks, etc. Areas of hooks may be
configured as discrete, discontinuous shapes entirely surrounded by
areas not occupied by hooks, as may be seen in FIGS. 9B, 9D and 9E
(sometimes known as "islands-in-the-sea" configurations).
Continuous areas of hooks may be configured to entirely surround
discrete, discontinuous shapes of areas not occupied by hooks, as
may be seen in FIG. 9A. Any combination of these two features is
also contemplated, for example, the configuration shown in FIG.
9C.
[0061] Features of an "integrally-formed" fastening member are
disclosed in US 2014/0200543, U.S. Pat. Nos. 9,333,125 and
9,068,912. Referring to FIG. 9 of the '125 patent, for example,
such features may include first and second surface layers (62 and
63, in FIG. 9 of the '125 patent) that extend continuously from a
proximal portion of the fastening member to a distal end. As
described in the '125 patent, a fastener such as a patch of hooks
may be affixed to one of the surface layers at a location proximate
the distal end. The fastening member may be elasticized to have
elastic stretch capability as described in the '125 patent,
including by way of inclusion of an elastomeric material layer (64,
in the '125 patent) disposed between the surface layers, in a
laminate. The described fastening member construction provides an
integrated structure for a fastening member, that may be
efficiently manufactured and eliminates any need for a separate
tape tab with hooks to be affixed to a distal end of the
member.
[0062] Features and construction of the fastening members described
in the '125 patent and/or '912 patent and/or '543 application may
be combined with integrally-molded hooks as described herein,
whereby integrally molded hooks are formed on the fastening members
in substitution for the separate patches of hooks material
described in the references. Additionally, or alternatively,
integrally molded hooks may be formed in the front waist region, on
the landing zone or elsewhere in the front waist region, in lieu of
the patches of hooks material described in the references.
[0063] Referring to FIGS. 8G and 8H, for example, a laminate web
211 may be formed of first layer 211a and second layer 211b. Layers
211a, 211b may sandwich and be laminated about an elastic material
217a, which may in some non-limiting examples an elastomeric film,
to form an elasticized zone 217b of the laminate web 211. The
layers may be affixed together to form a laminate via any suitable
means, including for example adhesive bonding and/or mechanical
bonding between the layers. The laminate 211 may comprise a
gathered laminate, wherein one of the layers is strained to a
greater degree than a remaining layer during lamination. In this
way, the less extensible layer (i.e., a nonwoven) will form gathers
when the laminate is in a relaxed state. Corrugations then form in
the nonwoven layer(s) when the subsequently formed laminate is in a
relaxed state. The laminate may comprise an ultrasonically bonded
laminate as is disclosed for example in U.S. Pat. Pub. Nos.
2018/0042777, 2018/0042778; 2018/0271716; and 2018/0271717.
Alternatively, the laminate 211 may be incrementally stretched, or
may be activated by processes disclosed in U.S. Pat. Pub. No.
2013/0082418, U.S. Pat. Nos. 4,834,741; 5,167,897; 5,993,432;
5,156,793; 5,167,897; 7,062,983 and 6,843,134 for example. The web
may be incrementally stretched or activated in the cross direction
through the elasticized zone 217b, as is known in the art, to
impart the web 211 and thereby fastening members to be cut
therefrom, with elastic stretch and contraction capability along
the cross direction, in the elasticized zone. As part of the
manufacturing process, areas of integrally molded hooks 212 may be
formed as described herein on portions of the web proximate to
distal ends of fastening members to be cut from the web, as
demarked by fastening member cut paths 124. Combining integrally
molded hooks with other features of fastening members described in
the '125 and '912 patents provides for an even more integrated and
efficiently manufactured fastening member than that described in
the referenced patents.
[0064] As indicated, the fastening member 120 may be formed
discretely from the chassis. This may permit separate orientation
of the fastening member and the chassis, or chassis components,
during manufacturing, providing a greater degree of freedom in
equipment set up, process steps and/or final diaper design.
[0065] Loops Material; Combination with Integrally Molded Hooks
[0066] In some examples, a nonwoven material may be manufactured
using the method described above, such that the material possesses
structure making it suitable for serving as both loops material and
as hooks material. In nonlimiting examples, such nonwoven material
may serve as the backsheet or a portion of the backsheet of the
article 10. Spunbond nonwoven material may be manufactured for use
in its entirety, or in one or more discrete sections, as loops
material to be used as the loops fastening component of a
hook-and-loop fastening system.
[0067] In some examples, the nonwoven material may be formed
primarily or entirely of single-component spun filaments. In other
examples, the manufacturing equipment and materials selections may
be configured and adapted to spin bi-component or multi-component
filaments, having differing, discrete portions of differing polymer
composition extending along their spun lengths. As a result of
differential rates and extents of contraction of these differing
portions upon cooling, bi-component or multi-component filaments
may tend to curl or crimp following spinning, making them
particularly suitable for making loops material.
[0068] Returning to FIGS. 6A-6C, in some examples, filaments 201
are spun and directed to and deposited on a conveyor surface 202 to
form a batt 203, as described above, under process conditions that
impart a machine direction bias to the filaments. The batt may then
be passed into the nip between a pair of calender/bonding rollers
as described above, resulting in a bonded nonwoven web in which the
filaments have a machine direction bias. To make the resulting
bonded nonwoven web material, or sections thereof, suitable for use
as loops material, the pattern of bonding protrusions 205 on the
bonding roller 204 may be configured with features that ensure that
most or all of the filaments of the intended section of loops
material 300 are bonded in a suitable bonding pattern 310, such
that they serve as effective, relatively closely-bound loops
structures. Thus, when the filaments have a machine direction bias,
it may be advantageous that the pattern of bonds have certain
geometric characteristics, for at least the section(s) of the web
to intended to serve as loops material 300.
[0069] Herein, a "section of loops material" 305 is any continuous
section or continuous portion of nonwoven web material formed of
spun filaments having a machine direction bias, the section or
portion having a machine direction dimension of at least 20 mm, a
cross direction dimension of at least 20 mm, and a surface area of
at least 314 mm.sup.2, which section or portion is calender bonded
in a pattern of loops-forming bonds having geometric features as
described below.
[0070] The geometric features may include conformity with geometric
constraints on any paths of unbonded areas across the section or
portion of material. FIGS. 10A-10I and 11A-11C schematically depict
intended loops material 300 of the minimum machine- and
cross-direction dimensions set forth above and bonded in various
patterns 310. As will be further explained, the examples of
patterns depicted meet, or do not meet, one or both of the
constraints described below. The table below summarizes the extent
to which these various examples meet the constraints described.
[0071] First Constraint: The section of intended loops material 300
may include one or more identifiable linear paths. By "identifiable
linear path", it is meant that a path (a) has a width greater than
2 mm and (b) forms an angle of 45 degrees or less with the machine
direction, in x-y plane along a major surface of the section of
intended loops material. In the figures, examples of such
identifiable linear paths are labeled "P0", "P45", and "P<45",
where P0 is aligned with the machine direction (forms an angle
therewith of 0 degrees); P45 forms an angle of 45 degrees with the
machine direction; and P<45 forms an angle with the machine
direction greater than 0 degrees and less than 45 degrees.
[0072] A first constraint that may be desirable is that every
identifiable linear path along the section of intended loops
material at least partially overlies a bond or bonds 213 in the
pattern 310 at a plurality of locations along the path.
[0073] Second Constraint: The maximum identifiable dimension, PFL,
between locations at which bonds are overlaid by any identifiable
linear path is from 1 mm to 12 mm, more preferably from 2 mm to 10
mm, and even more preferably from 2 mm to 8 mm.
[0074] The following table summarizes the extent to which the
examples of bond patterns depicted in FIGS. 10A-10I and 11A-11C
meet the first and second constraints described above:
TABLE-US-00001 FIG.(S) First Constraint Second Constraint 10A, 10B
Met - every identifiable linear path greater than Met, if PFL is
within one 2 mm wide, forming an angle of 45 degrees or of the
ranges specified in less with machine direction MD (e.g., paths P0,
description above P45), overlies bonds 213 at a plurality of
locations 10C Not met - identifiable path P45 does not overlie Not
met - PFL has no bonds 213 at any locations finite value 10D Not
met - identifiable path P<45 does not Not met - PFL has no
overlie bonds 213 at any locations finite value 10E Not met -
identifiable path P0 does not overlie Not met - PFL has no bonds
213 at any locations finite value 10F, 10G, 10H Met - every
identifiable linear path greater than Met, if PFL is within one 2
mm wide, forming an angle of 45 degrees or of the ranges specified
in less with machine direction MD (e.g., paths P0, description
above P45), overlies bonds 213 at a plurality of locations 10I Not
met - identifiable path P0 does not overlie Not met - PFL has no
bonds 213 at any locations finite value 11A Met - every
identifiable linear path greater than Met, if PFL is within one 2
mm wide, forming an angle of 45 degrees or of the ranges specified
in less with machine direction MD (e.g., paths P0, description
above P45), overlies bonds 213 at a plurality of locations 11B Not
met - identifiable path P0 does not overlie Not met - PFL has no
bonds 213 at any locations finite value 11C Met - every
identifiable linear path greater than Met, if PFL is within one 2
mm wide, forming an angle of 45 degrees or of the ranges specified
in less with machine direction MD (e.g., paths P0, description
above P45), overlies continuous bond 213 (continuous region shown
in black) at a plurality of locations (unbonded areas are discrete
white circular areas 213a)
[0075] Configuring the bond pattern in observance of one or both
the first and second geometric restrictions described above,
minimizes the likelihood that substantial numbers of excessively
long, unbonded lengths of filaments of the nonwoven web material,
which are generally not suitable as loops structures, will be
present. Conversely, observance of one or both of these
restrictions provides that the substantially greater proportion of
filaments making up the nonwoven web material will be bonded down
to the web at intervals a suitable distance apart, making them
suitable to perform as loops structures. With respect to the second
constraint, a lower limit on the distance between bonds may be
desired so that unbonded lengths of filaments are not too short to
be accessible to hooks so as to be effectively engageable
therewith; and an upper limit on the distance between bonds may be
desired so that unbonded lengths of filaments are not too long to
provide close engagement and holding strength when the section of
loops material is engaged with hooks.
[0076] In conjunction with one or both of the geometric constraints
described above, it may be desired to specify a range for the
quantity of bonded surface area as a percentage of total surface
area [typically expressed as "bond area percentage," or similar
expression, calculated as (bonded area)/(total area).times.100%].
If the bond area percentage is too low, there may be an
insufficient amount of bonding to impart holding strength to the
section of material. If the bond area percentage is too high, too
many of the filaments and/or too much of their length will be
rendered unavailable to engage hooks. Accordingly, it may be
desired that the bond area percentage be controlled (via design of
the bonding pattern) to be from 5 percent to 40 percent, more
preferably from 8 percent to 25 percent, and even more preferably
from 10 percent to 20 percent.
[0077] Alternatively, or in addition to the observance of the
constraints described above, a section of intended loops material
300 may be bonded in a pattern according to any of the non-limiting
examples described in U.S. Pat. No. 7,789,870.
[0078] To determine whether a bonding pattern conforms with the
constraints and features described above, the pattern as visible on
the nonwoven material may be viewed and measured by direct
examination of the material (machine-assisted to any extent deemed
helpful). It will be understood, however, that the geometric
arrangement of a pattern of bonds impressed on a calender-bonded
nonwoven web material will correspond approximately with the
geometric arrangement of the pattern of bonding protrusions on the
calender bonding roller used to bond the web. Accordingly, as an
alternative to measuring the geometric arrangement of the bonding
pattern by direct examination of the nonwoven web, the geometric
arrangement of the bonding protrusions as formed on the calender
roller may be examined and measured. In still another alternative,
the geometric arrangement of the bonding protrusions as formed on
the calender roller may be discerned from the specifications and/or
mechanical drawings used to produce the calender roller. To the
extent there may be some variance, between the geometric
arrangement of the bonding protrusions on the calender roller as
set forth in the specifications and/or mechanical drawings for the
calender roller, the actual geometric arrangement of bonding
protrusions on the calender roller, and the resulting actual
geometric arrangement of the pattern of bonds impressed on
calender-bonded nonwoven web material, the deviation is deemed to
be within contemplation and scope of the numerical values for the
constraints as described herein. Accordingly, if any of:
[0079] (a) the pattern of bonds actually present on the nonwoven
web material,
[0080] (b) the pattern of bonding protrusions actually present on
the associated calender bonding roller, or
[0081] (c) the pattern of bonding protrusions for the calender
bonding roller as set forth in the specifications and/or mechanical
drawings associated with the roller are in conformity with the
geometric features and constraints described above, the pattern is
deemed to be within contemplation and scope of the same.
[0082] A nonwoven material that is both adapted to serve as a loops
material and has integrally molded areas of hooks formed therein,
may be deemed useful for diapers with hook-and-loop fastening
systems sometimes known as "multipoint" systems, or systems having
"primary" and "secondary" pairs of hooks and loops, such as
disclosed, in, for example, U.S. Pat. Nos. 9,265,673; 9,339,425;
9,597,237; US 2017/065,468; U.S. Pat. Nos. 9,615,980 and
9,265,674.
Examples of Configurations
[0083] FIGS. 12A-12E depict examples of sections of nonwoven web
material 214 that might be included as, or as part of, a landing
zone 130 on the front waist region of a diaper 101 (FIGS. 1 and 3).
Section of nonwoven web material 214 may be bonded in a pattern of
bonds that make it suitable for serving as loops material 300, for
example a section of loops material 305 as described above.
Additionally, section of nonwoven web material 214 may include
areas of hooks 212 that are integrally molded on the material as
described above. It will be appreciated that methods described
herein may be used to form such sections and as such may be used to
provide a nonwoven web material that includes both hooks and loops,
without the need for process steps associated with supplying,
applying and adhering or bonding previously manufactured hooks
material, as a separate component, to the nonwoven web material. In
nonlimiting examples, the section of nonwoven web material 214 may
comprise a section of the article's backsheet 112. The section of
nonwoven web material 214 may be discrete from the backsheet 112.
By way of nonlimiting example, a section of nonwoven material 214
having hooks and loops material located in the rear waist region
may be discrete from the backsheet, as shown for example in FIG.
13A. In further nonlimiting example, a section of nonwoven material
214 having hooks and loops material located in the front waist
region may be integral with the backsheet.
[0084] The areas of hooks 212 may be configured so as to reduce the
likelihood that hooks will contact the wearer's skin, along
locations proximate the lower outside corners of the landing zone
130, should the diaper tend to bunch or fold at those locations,
during wear. To provide such advantage, each area of hooks 212 may
be configured that no hooks are present in the configuration within
a 45-45-90 right triangle 217 with legs 5 mm in length, occupying
the lower outside corner of a rectangle 215, with two sides
parallel/along the lateral direction, drawn to entirely
circumscribe the hooks area(s) present. It can be seen that the
examples of hooks area 212 configurations in each of FIGS. 12A-12E
all satisfy this condition. Accordingly, these nonlimiting examples
would reduce the likelihood that hooks in the hooks areas 212 would
contact the wearer's skin during wear of the diaper.
[0085] As shown in FIG. 12F, when applied to the chassis, a
longitudinal edge 304 of the web material 214 may extend outboard
of the chassis longitudinal edge 117. Additionally, or
alternatively, the section of web material 214 may comprise a
curvilinear longitudinal edge 304. The curvilinear shape may have
at least two convexities 401 and 402 and at least one concavity 403
disposed intermediate the two convexities. Without wishing to be
bound by theory, it is believed this embodiment allows the belt to
fit smoothly into the body's complex geometry and provides a more
comfortable wearing experience by allowing the wearer's legs to
move with less hindrance from material (i.e., the belt is narrower
near the upper thighs) while maintaining a secure fit around the
waist. In addition, minimizing the amount of material proximate to
the inboard edge reduces the likelihood of the material folding
over when positioned beneath under the back ear during application,
and thereby increases fit and comfort.
[0086] FIGS. 13A-13C depict non-limiting examples of configurations
of features for diapers with hook-and-loop fastening systems that
are contemplated herein. Referring to FIG. 13A, front waist region
101 may include a landing zone 130 formed by, or including, a
section of web material 214 on which one or more areas of hooks
212F are integrally molded as described herein. Section of web
material 214 may be adapted to serve as loops material 300, such as
a section of loops material 305 with a pattern of bonds as
described herein, so as to fastenably engage with areas or patches
of hooks 212R attached to or integrally molded on fastening members
120 as described herein. Fastening members 120 may similarly be
formed at least in part of a section of web material adapted to
serve as loops material 305, so as to fastenably engage with hooks
212F. In this configuration, two pairs of hook-and-loop
combinations engage each other to provide benefits associated with
combinations of primary and secondary fastening pairs.
[0087] Referring to FIG. 13B, it is further contemplated that hooks
on fastening members 120 might be omitted entirely, when fastening
members 120 are formed of or include loops material such as the
section of loops material 305 as described herein. Correspondingly,
loops on landing zone 130 may be omitted entirely, and all that is
present is section of web material 214 bearing integrally molded
areas of hooks 212F. Hooks 212F and loops material of fastening
members 120 may be adapted to fastenably engage.
[0088] In some embodiments, the backsheet 112 may comprise loop
material and integrally molded areas of hooks 212F might be formed
directly on, and be integral with, the backsheet 112. In such
embodiments, fastening members 120 may include hooks, integrally
formed thereon or attached as discrete patches. Likewise, the
fastening members 120 may include loop material to engage with the
areas of hooks 212F.
[0089] Further, referring to FIG. 13C, it is contemplated also that
hooks on fastening members 120 might be omitted entirely, when
fastening members 120 are formed of or include loops material such
as nonwoven web material adapted to serve as loops material as
described herein; and a section of web material separate from the
backsheet, to be applied to the front waist region, might be
omitted. Rather, integrally molded areas of hooks 212F might be
formed directly on, and be integral with, component material(s)
forming nonwoven web material used as an outer layer for the diaper
backsheet 112. Hooks 212F on the front waist region and loops
material included with fastening members 120 may be adapted to
fastenably engage.
[0090] By suitably configuring the hooks-forming cavities in the
hooks-forming roller, areas of hooks 212F and 212R may be
configured with varying directionality. Some hooks structures in
currently marketed hooks materials lack directionality; others have
singular directionality or bi-directionality along a single line.
Each of FIGS. 14A-16C depicts a front view 220, side view 221 and
top view 222 of one of three non-limiting examples of hook shapes,
protruding or emerging from a substrate 223. (Substrate 223 may be
the material such as a nonwoven web material as described herein,
from which the hooks are integrally molded.) Referring to FIGS.
14A-14C, this type of hook shape (sometimes described as a
"mushroom" shape) lacks directionality because it is substantially
symmetrical about all planes along its vertical (z-direction) axis
and/or has substantially similar front and side view profiles.
Other types of hook shapes may be formed to have directionality
such that they lack such symmetry and/or similarity of front and
side views. The hook shape example reflected in FIGS. 15A-15C is
substantially unidirectional in that it hooks over predominately in
one direction 1HD. The hook shape reflected in FIGS. 16A-16C
(sometimes described as an "arrowhead" shape) is substantially
bi-directional in that it has two opposing arms 224 that hook over
in two opposite directions 2HD.
[0091] Returning to FIGS. 12A-E and 13A-C, hooks in areas 212, 212F
may be imparted with unidirectionality or bidirectionality along a
lateral direction (with respect to a diaper on which the hooks are
disposed), or along any direction that is 45 degrees or less from
(i.e., approaching) the lateral direction. In a more particular
example, hooks in the respective left and right areas 212 and 212F
may be imparted with directionality approaching or along the
lateral direction and extending toward the longitudinal axis of the
diaper. Such directionality provides mechanical structure extending
in a direction opposite the ordinary direction of shear forces
(directed away from the longitudinal axis in the front region of
the diaper) that would be exerted on the hooks in areas 212F while
the hooks are engaged with a fastening member 120 while the diaper
is being worn. As a result, the fastening strength is increased
and/or attachment is more secure, as compared with non-directional
hooks of similar size, material utilization (shape volume) and
numerical density. In addition, such directionality can reduce skin
abrasion caused by contact with hooks as the configuration results
in a softer side/surface of the hooks contacting the skin, to the
extent contact occurs.
[0092] Referring to FIG. 13A, the hooks 212R on fastening member
120 may be imparted with directionality toward the longitudinal
axis of the diaper (when the fastening member is in the open
position as shown). Such directionality would oppose the ordinary
direction of shear forces that would be exerted on the hooks in
areas 212F while the hooks are engaged with a fastening member 120
while the diaper is being worn, providing for added fastening
strength and/or more secure attachment, as compared with
non-directional hooks of similar size, material utilization (shape
volume) and numerical density.
[0093] In any of the foregoing examples, fastening members 120 may
comprise a laminate 311, as shown in FIG. 13B for example. The
laminate 311 may be formed of the section of nonwoven web material
adapted to serve as loops material 300 as described herein and an
elasticizing member 317 such as a layer of elastomeric film, or a
plurality of longitudinally spaced, laterally-oriented strands of
elastomeric material. The elastomeric member(s) may be joined with
the nonwoven loops material while the elastomeric member(s) is(are)
in a laterally strained condition, such that the nonwoven loops
material forms ruffles or gathers of laterally gathered nonwoven
material upon relaxation of the elastomeric member(s) and imparts
elastic stretchability to the fastening member when the diaper is
donned on a wearer. The laminate may be bonded by ultrasonic bonds,
mechanical bonds, adhesive bonds, and any combinations thereof.
Alternatively, the elasticized member may be joined to the loops
material at zero relative strain and subsequently activated to
produce elasticity.
[0094] It is also contemplated that loops material may be disposed
on a separate substrate from hooks. For example, loops material 300
may be supplied as a separate patch and attached to the chassis,
while hooks may be integrally formed from the backsheet.
[0095] Hysteresis Test
[0096] The following test methods utilize a commercial tensile
tester (e.g., from Instron Engineering Corp. (Canton, Mass.),
SINTECH-MTS Systems Corporation (Eden Prairie, Minn.) or
equivalent) interfaced with a computer. The computer is used to
control the test speed and other test parameters and for
collecting, calculating, and reporting the data. The tests are
performed under laboratory conditions of 23 deg. C.+-2 deg. C. and
relative humidity of 50%+-2%. The samples are conditioned for 24
hours prior to testing.
[0097] 1. Select a 2.54 cm (width), 7.62 cm (length) sample of the
material for testing. In some cases, if it is not be possible to
get a 2.54 cm.times.7.62 cm sample, a smaller sample may be used,
but a gage length of 25 mm must still be used. If the sample is
activated or includes an activation portion, the length of the
sample is taken in the direction of activation.
[0098] 2. Select the appropriate jaws and load cell. The jaws must
have flat surfaces and must be wide enough to fit the sample (e.g.,
at least 2.54 cm wide). Also, the jaws should provide adequate
force to ensure that the sample does not slip during testing. The
load cell is selected so that the tensile response from the sample
tested is between 25% and 75% of the capacity of the load cell
used.
[0099] 3. Calibrate the tester according to the manufacturer's
instructions.
[0100] 4. Set the distance between the grips at 25 mm.
[0101] 5. Place the sample in the flat surface of the jaws such
that the longitudinal axis of the sample is substantially parallel
to the gauge length direction. Mount the sample with minimal slack.
Set the slack preload at 0.02 N/cm. This means that the data
collection starts when the slack is removed with a force of 0.02
N/cm. Strain is calculated based on the adjusted gauge length
(lini), which is the length of the sample in between the grips of
the tensile tester at a force of 0.02 N/cm. This adjusted gauge
length is taken as the initial sample length, and it corresponds to
a strain of 0%. Percent strain at any point in the test is defined
as the change in length divided by the adjusted gauge length times
100%.
[0102] 6(a) First cycle loading: Pull the sample to a strain of 50%
at a constant cross head speed of 254 mm/min.
[0103] 6(b) First cycle unloading: Hold the sample at 50% strain
for 30 seconds and then return the crosshead to its starting
position (0% strain) at a constant cross head speed of 254 mm/min.
Hold the sample in the unstrained state for 1 minute.
[0104] 6(c) Set from second cycle loading: Pull the sample at a
constant cross head speed of 254 mm/min, till it reaches a load of
0.05 N/25.4 mm (0.020 N/cm). Record the extended gauge length
(lext). Next, return the crosshead to its starting position (zero
strain) at a constant cross head speed of 254 mm/min. Set is
defined as the strain at a second cycle load of 0.05 N/25.4 mm
(0.020 N/cm). Calculate % set as indicated below.
[0105] 6(d) Second cycle unload: Next, return the crosshead to its
starting position (zero strain) at a constant cross head speed of
254 mm/min.
[0106] Percent Set is defined as the percent strain at a second
cycle load of 0.05 N/25.4 mm (0.020 N/cm). Calculate % set as
indicated below.
[0107] A computer data system records the force exerted on the
sample during the test as a function of applied strain. From the
resulting data generated, the following quantities are reported
(note that loads are reported as force divided by the width of the
sample and do not take into account the thickness of the
sample):
[0108] 1. Loads at 25% strain and 50% strain (N/cm)
[0109] 2. % set (Percent Strain measured at a second cycle load of
0.02N/cm);
[0110] 3. % set=(lext-lini)/lini*100%.
[0111] Five repetitions are done on each sample and the average and
standard deviation reported.
[0112] The Hysteresis Test can be suitably modified depending on
the expected attributes and/or properties of the particular
material sample to be measured. For example, the Test can be
suitably modified where a sample of the length and width specified
above are not available from the subject article.
[0113] The dimensions and values disclosed herein are not to be
understood as being strictly limited to the exact numerical values
recited. Instead, unless otherwise specified, each such dimension
is intended to mean both the recited value and a functionally
equivalent range surrounding that value. For example, a dimension
disclosed as "40 mm" is intended to mean "about 40 mm."
[0114] Every document cited herein, including any cross referenced
or related patent or application, is hereby incorporated herein by
reference in its entirety unless expressly excluded or otherwise
limited. The citation of any document is not an admission that it
is prior art with respect to any invention disclosed or exampled
herein or that it alone, or in any combination with any other
reference or references, teaches, suggests or discloses any such
invention. Further, to the extent that any meaning or definition of
a term in this document conflicts with any meaning or definition of
the same term in a document incorporated by reference, the meaning
or definition assigned to that term in this document shall
govern.
[0115] While particular embodiments of the present invention have
been illustrated and described, it would be obvious to those
skilled in the art that various other changes and modifications can
be made without departing from the spirit and scope of the
invention. It is therefore intended to cover in the appended
examples all such changes and modifications that are within the
scope of this invention.
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